Method and device for measuring gear tooth wear
A method and device for measuring an amount of wear on a flank of a gear tooth is provided. The method includes positioning a template comprising a first template tooth adjacent a gear comprising a first gear tooth. The method also includes adjusting the position of the template in a rotational direction with respect to a known rotational reference point of the gear, adjusting the position of the template in an axial direction with respect to a known axial reference point of the gear, and adjusting the position of the template in a radial direction with respect to a known radial reference point of the gear. The method further includes measuring an extent of a gap between an edge of the first template tooth and an adjacent flank of the first gear tooth, wherein the gap corresponds to the amount of wear on the flank.
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The subject matter described herein generally relates to gear teeth and, more particularly, to a method and device for measuring gear tooth wear.
BACKGROUND OF THE INVENTIONAt least some known wind turbines include a rotor having multiple blades. The rotor blades are sometimes coupled to a hub that is in turn coupled to a housing, or nacelle. The nacelle is positioned on top of a base, for example, a truss or tubular tower. The rotor blades transform mechanical wind energy into induced blade lift forces that further induce a mechanical rotational torque. The induced torque is used to drive one or more generators, subsequently generating electric power, or alternatively to pump a fluid and/or grind a substance.
At least some known wind turbines have a mechanism to adjust a pitch angle of each rotor blade. The pitch angle is an angle that determines each of the blades' orientation about a longitudinal axis of the blade. At least some known pitch adjustment mechanisms include a pitch motor operating a pinion gear that acts on a ring gear coupled to the blade.
In at least some known wind turbines, a plurality of teeth of the ring gear may become worn over time, decreasing an efficiency and reliability of the pitch adjustment mechanism. Moreover, an extent of such gear tooth wear is difficult to quantify. Templates are known that may be inserted between the flanks of adjacent gear teeth, allowing a wear of the gear teeth to be estimated by comparing a distance between the adjacent flanks to a known template width. However, such known templates provide only an estimation of a combined wear on both flanks of the two adjacent teeth, rather than a measurement of the wear on an individual tooth flank. Moreover, such known templates do not provide a repeatable measurement at a consistent location on each tooth flank that may be used to compare wear between two different times for a given gear tooth, between one gear tooth and another gear tooth on the same gear, or between gear teeth on similar gears associated with different blades or different wind turbines. Accordingly, it would be desirable to develop a method and/or a system that facilitates a repeatable and reliable measurement of the wear at a consistent location on each flank of each gear tooth.
BRIEF DESCRIPTION OF THE INVENTIONIn one aspect, a method of measuring an amount of wear on a flank of a gear tooth is provided. The method includes positioning a template comprising a first template tooth adjacent a gear comprising a first gear tooth. The method also includes adjusting the position of the template in a rotational direction with respect to a known rotational reference point of the gear, adjusting the position of the template in an axial direction with respect to a known axial reference point of the gear, and adjusting the position of the template in a radial direction with respect to a known radial reference point of the gear. The method further includes measuring an extent of a gap between an edge of the first template tooth and an adjacent flank of the first gear tooth, wherein the gap corresponds to the amount of wear on the flank.
In another aspect, a template for measuring an amount of wear on a first gear tooth of a gear is provided. The template includes a first template tooth configured to fit in a space defined between the first gear tooth and a second gear tooth adjacent the first gear tooth, such that an edge of the first template tooth abuts a flank of the first gear tooth with substantially no gaps when the flank is in an unworn condition. The template is configured to be repeatably positionable at a consistent location with respect to an axial direction defined with respect to the gear, a radial direction defined with respect to the gear and a rotational direction defined with respect to the gear. A measurable gap between the edge and the flank corresponds to the amount of wear on the first gear tooth.
In yet another aspect, a system for comparing gear tooth wear is provided. The system includes a plurality of gears of substantially similar size and shape, with each gear having a first gear tooth, a second gear tooth adjacent the first gear tooth, and a space defined therebetween. The system also includes a template having a first template tooth configured to fit in the space such that an edge of the first template tooth abuts a flank of the first gear tooth with substantially no gaps when the flank is in an unworn condition. The template is configured to be repeatably positionable at a consistent location on each of the plurality of gears with respect to an axial direction defined with respect to each gear, a radial direction defined with respect to each gear and a rotational direction defined with respect to each gear. A measurable gap between the edge and the flank corresponds to an amount of wear on the first gear tooth of each gear of the plurality of gears.
The method and system described herein facilitate a repeatable and reliable measurement of the wear at a consistent location on each flank of each gear tooth. Such method and system includes the use of a template that is positionable with respect to a consistent reference point on a gear. The template includes at least a first template tooth configured to fit in a space defined between a first and second tooth of a gear. Specifically, the template is positionable at a consistent location with respect to an axial direction, a radial direction and a rotational direction defined with respect to the gear. A technical effect of the template is to allow a repeatable measurement of the wear on each tooth flank that may be used to compare gear tooth wear at two different times for a given gear tooth on a single gear, or between one gear tooth and another gear tooth on the same gear, or between gear teeth on a plurality of gears of a substantially similar size and shape.
Wind turbine 10 includes a body 12, sometimes referred to as a “nacelle,” and a rotor (generally designated by 14) coupled to body 12 for rotation with respect to body 12 about an axis of rotation 16. In the exemplary embodiment, nacelle 12 is mounted on a tower 18. The height of tower 18 is any suitable height enabling wind turbine 10 to function as described herein. Rotor 14 includes a hub 20 and a plurality of blades 22 (sometimes referred to as “airfoils”) extending radially outwardly from hub 20 for converting wind energy into rotational energy. Although rotor 14 is described and illustrated herein as having three blades 22, rotor 14 may include any number of blades 22.
In the exemplary embodiment, pitch control system 24 includes a pinion gear 30. When wind turbine 10 is in normal operation, pinion gear 30 is driven by one or more actuators (not shown), such as, but not limited to, electrical motors, hydraulic cylinders, springs, and/or servomechanisms. Pinion gear 30 cooperates with a ring gear 40, through an interaction of gear teeth as described below and shown in
More specifically, in the exemplary embodiment, template 60 includes a plurality of teeth 62 that are shaped to fit in respective spaces between adjacent ring gear teeth 42 when template 60 is fitted adjacent to ring gear 40. If the ring gear teeth 42 are in a new or unworn condition, a forward edge 64 of each template tooth 62 fits snugly, with no gaps, against the respective forward flank 44 of a ring gear tooth 42, and a rear edge 66 of each template tooth 62 fits snugly, with no gaps, against the corresponding rear flank 46 of a ring gear tooth 42. Moreover, as material on the forward flanks 44 and rear flanks 46 of gear teeth 42 is worn away through interaction with pinion gear teeth 32, measurable gaps will become apparent between forward edges 64 and forward flanks 44, and between rear edges 66 and rear flanks 46, when template 60 is fitted adjacent to ring gear 40. For clarity in
In certain embodiments, template 60 is positionable with respect to a consistent reference point on ring gear 40. More specifically, in certain embodiments, template 60 is repeatably positionable at a consistent location with respect to an axial direction 100, which lies parallel to longitudinal axis 26 (shown in
In the exemplary embodiment, template 60 includes at least one leg 70 that facilitates consistent positioning of template 60 with respect to axial direction 100. Each leg 70 is shaped to contact a respective end 52 of a gear tooth 42 when template 60 is positioned adjacent ring gear 40. Legs 70 are sized such that, when legs 70 are each in contact with a respective end 52 as shown in
Moreover, in the exemplary embodiment, consistent alignment of template 60 with respect to radial direction 102 is facilitated by a plurality of bottom lands 68 of template teeth 62 that are shaped to contact respective top lands 48 of gear teeth 42 when template 60 is fitted adjacent to ring gear 40. As described previously, in normal operation, no direct wear occurs on ring gear teeth top lands 48. As a result, ring gear teeth top lands 48 lie at an approximately constant radial distance from longitudinal axis 26 of ring gear 40 over the life of ring gear 40, and template 60 may be consistently located with respect to radial direction 102 by bringing template teeth bottom lands 68 into contact with respective ring gear teeth top lands 48. In alternative embodiments, template 60 may, for example but not by way of limitation, have a shape that facilitates contact or visual alignment with ring gear teeth bottom lands 49 or other known radial reference point of ring gear 40.
Further, in the exemplary embodiment, consistent alignment of template 60 with respect to rotational direction 104 is facilitated by locating an unused ring gear tooth 142 within a first template space 72 when template 60 is fitted adjacent to ring gear 40. First template space 72 is selected to be the space defined between any two adjacent template teeth 62. In the exemplary embodiment, as shown in
Also with reference to
Exemplary embodiments of methods and devices for measuring gear tooth wear are described above in detail. The methods and devices are not limited to the specific embodiments described herein, but rather, components of systems and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein. For example, the steps of the methods may be performed in any appropriate order, and the methods may also be used in combination with gears in other applications, and are not limited to practice with only a wind turbine ring gear as described herein. Rather, the exemplary embodiment can be implemented and utilized in connection with many other gear applications.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
Claims
1. A method of measuring an amount of wear on a flank of a gear tooth, said method comprising:
- positioning a template comprising a first template tooth adjacent a gear comprising a first gear tooth;
- adjusting the position of the template in a rotational direction with respect to a known rotational reference point of the gear;
- adjusting the position of the template in an axial direction with respect to a known axial reference point of the gear;
- adjusting the position of the template in a radial direction with respect to a known radial reference point of the gear; and
- measuring an extent of a gap between an edge of the first template tooth and an adjacent flank of the first gear tooth, the gap corresponds to the amount of wear on the flank.
2. A method in accordance with claim 1 wherein the gear comprises a second gear tooth, said positioning a template comprises positioning the template such that the first template tooth fits in a space defined between the first gear tooth and the second gear tooth.
3. A method in accordance with claim 1 wherein the template further comprises a second template tooth, a third template tooth, and a first template space defined therebetween, and the gear further comprises an unused gear tooth, said adjusting the position of the template in a rotational direction with respect to a known rotational reference point of the gear comprises positioning the unused ring gear tooth within the first template space.
4. A method in accordance with claim 1 wherein said adjusting the position of the template in a rotational direction with respect to a known rotational reference point of the gear comprises visually aligning the template with the known rotational reference point of the gear.
5. A method in accordance with claim 1 wherein the template comprises at least one leg and the gear comprises a second gear tooth, said adjusting the position of the template in an axial direction with respect to a known axial reference point of the gear comprises adjusting the position of the template such that the at least one leg contacts an end of the second gear tooth.
6. A method in accordance with claim 1 wherein said adjusting the position of the template in an axial direction with respect to a known axial reference point of the gear comprises visually aligning the template with an axial edge of the gear.
7. A method in accordance with claim 1 wherein the first gear tooth comprises a top land and the first template tooth comprises a bottom land, said adjusting the position of the template in a radial direction with respect to a known radial reference point of the gear comprises adjusting the position of the template in a radial direction such that the first template tooth bottom land contacts the first gear tooth top land.
8. A method in accordance with claim 1 wherein said measuring an extent of a gap between an edge of the first template tooth and an adjacent flank of the first gear tooth further comprises inserting a feeler gage into the gap at a location defined by a marking on the first template tooth.
9. A template for measuring an amount of wear on a first gear tooth of a gear, said template comprising a first template tooth configured to fit in a space defined between the first gear tooth and a second gear tooth adjacent the first gear tooth such that an edge of said first template tooth abuts a flank of the first gear tooth with substantially no gaps when the flank is in an unworn condition, said template is configured to be repeatably positionable at a consistent location with respect to an axial direction defined with respect to the gear, a radial direction defined with respect to the gear and a rotational direction defined with respect to the gear, wherein a measurable gap between said edge and the flank corresponds to the amount of wear on the first gear tooth.
10. A template in accordance with claim 9 further comprising a second template tooth and a third template tooth defining a first template space therebetween, said first template space configured to accept an unused gear tooth of the gear to facilitate repeatable positioning of said template at the consistent location with respect to the rotational direction.
11. A template in accordance with claim 9 wherein the gear further comprises a rotational reference point, said template further configured for visual alignment with the rotational reference point to facilitate repeatable positioning of said template at the consistent location with respect to the rotational direction.
12. A template in accordance with claim 9 further comprising at least one leg, wherein the gear comprises a third gear tooth, said at least one leg configured to contact an end of the third gear tooth to facilitate repeatable positioning of said template at the consistent location with respect to the axial direction.
13. A template in accordance with claim 9 further configured for visual alignment of said template with an axial edge of the gear to facilitate repeatable positioning of said template at the consistent location with respect to the axial direction.
14. A template in accordance with claim 9 wherein the first gear tooth comprises a top land and said first template tooth comprises a bottom land, said template further configured such that said first template tooth bottom land contacts the first gear tooth top land to facilitate repeatable positioning of said template at the consistent location with respect to the radial direction.
15. A template in accordance with claim 9 wherein said first template tooth further comprises a marking configured to indicate a measurement location.
16. A system for comparing gear tooth wear comprising:
- a plurality of gears of substantially similar size and shape, each gear comprising a first gear tooth, a second gear tooth adjacent the first gear tooth, and a space defined therebetween; and
- a template comprising a first template tooth configured to fit in the space such that an edge of said first template tooth abuts a flank of said first gear tooth with substantially no gaps when said flank is in an unworn condition, said template configured to be repeatably positionable at a consistent location on each of the plurality of gears with respect to an axial direction defined with respect to each gear, a radial direction defined with respect to each gear and a rotational direction defined with respect to each gear, wherein a measurable gap between said edge and said flank corresponds to an amount of wear on said first gear tooth of each gear of said plurality of gears.
17. A system in accordance with claim 16, said template further comprising a second template tooth and a third template tooth defining a first template space therebetween, said first template space configured to accept an unused gear tooth of said gear to facilitate repeatable positioning of said template at the consistent location with respect to the rotational direction.
18. A system in accordance with claim 16, said template further comprising at least one leg, each gear of said plurality of gears comprising a third gear tooth, said at least one leg configured to contact an end of said third gear tooth to facilitate repeatable positioning of said template at the consistent location with respect to the axial direction.
19. A system in accordance with claim 16, said first gear tooth comprises a top land and said first template tooth comprises a bottom land, said template further configured such that said first template tooth bottom land contacts said first gear tooth top land to facilitate repeatable positioning of said template at the consistent location with respect to the radial direction.
20. A system in accordance with claim 16 wherein said first template tooth further comprises a marking configured to indicate a measurement location.
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Type: Grant
Filed: Oct 8, 2008
Date of Patent: Jun 8, 2010
Patent Publication Number: 20100083516
Assignee: General Electric Company (Schenectady, NY)
Inventors: Aaron John Mashue (Simpsonville, SC), Ryan Spencer Close (Greenville, SC)
Primary Examiner: Christopher W Fulton
Attorney: Armstrong Teasdale LLP
Application Number: 12/247,476
International Classification: G01M 13/02 (20060101);